КОМПЛЕКСИ НЕОДИМУ (ІІІ) ТА ЕРБіЮ (ІІІ) З НОВИМИ НЕНАСИЧЕНИМИ β-ДИКЕТОНАМИ 1 Інститут загальної та неорганічної хімії ім. В.І.Вернадського НАН України, просп. Академіка Палладіна, 32/34, Київ, 03142, Україна 2 Національний технічний університет України "Київський політехнічний інститут імені Ігоря Сікорського", просп.

New ytterbium (III) compounds with β-diketones (2,7-dimethyl-octene-1-dione-3,5 and 2,6-dimethylheptene-1-dione-3,5) and their derivatives with phenanthroline have been synthesized. The composition and chemical structure of the obtained complexes have been determined by several Phy­sico-chemical investigations. It has been shown, that the Yb (III) ion coordinates three ligand molecules and the coordination sphere of the complexes is supplemented by two mole­cules of water or a molecule of phenanthroline. It has been shown that the СN of the ytterbium ion is 8, the coordination polyhedron is a square antiprism, and the complex is characte­rized by no cubic symmetry. All synthesized compounds exhibit intense IR luminescence. The significant increase in the relative emission intensity of mixed ligand complexes is due to the additional antenna effect of the phenanthroline molecule.

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New heterometallic complexes of Сo(II) and Nd(III) with carboxylic acids (succinic, oxalic) and acetylacetone in the presence of phenanthroline or α,α'-dipyridyl have been synthesized. Their thermal properties and the ability to form complex oxides during thermal degradation have been studied. In the process of thermolysis of heterocomplexes, neodymium cobaltate NdCoO3 was obtained, which is confirmed by the results of X-ray powder diffraction. The research has established that the X-ray powder diffraction patterns of the products obtained by thermolysis of heterocomplex [Сo2Nd2(C4Н4O4)5·2Phen]·4Н2О to 1000 °С exhibits peaks at (2θ): 23.40, 33.74, 41.42, 48.32, 54.52, 59.94, 70.58°. This corresponds to the neodymium cobaltate NdCoO3. Neodymium cobaltate crystallizes in the cubic crystal system. The sample was obtained without extraneous phases inclusions. For the samples obtained by the termolysis of he­te­rocomplexes [Сo2Nd2(C2O4)5·2Phen]·4Н2О and NdCo(AA)5·2α,α'-dipy, in addition to the complex oxide NdCoO3, peaks of Nd2O3 were recorded, which crystallizes in the hexa­gonal crystal system. The X-ray powder diffraction patterns show peaks with 2θ values: 26.92, 29.75, 30.77, 40.54, 47.53, 53.63, 57.08°. The phase ratio of NdCoO3/Nd2O3 after termolysis for the sample of CoNd(AA)5·2α,α'-dipy is ~ 68.9/31.1%; for the sample of [Сo2Nd2(C2O4)5·2Phen]·4Н2О is ~ 50/50%; for the sample of [Сo2Nd2(C4Н4O4)5·2Phen]·4Н2О is NdCoO3 ~ 100%. The average crystallites size of complex oxides was calculated using the Scherer formula. It has been showed that neodymium cobaltate has an average particle size of ~33 nm, regardless of the complex precursor from which it was formed during thermolysis. The catalytic effect of neodymium cobaltates in the hydrogen peroxide decomposition reaction was studied. It was shown that all samples of complex oxides showed a quite high cataly­tic activity in the all of experiments in the hydro­gen peroxide decomposition reactions.

Spherical silver nanoparticles were synthesized by the chemical condensation method using aloe vera or chamomile extracts as a reducing agent. Depending on the type of extracts and its concentration, the size of AgNpcs varied from 7 to 50 nm by simply adjusting the ratio of the starting reagents. These extracts show reducing properties due to the presence of carbonyl compounds in their composition, in particular organic acids. It is shown that regu­lation of concentrations and synthesis conditions allows control of particle size. A change in the synthesis conditions affects the position of the surface plasmon resonance band, and therefore the optical properties of the studied systems. It has been proven that the synthesized silver nanoparticles do not require additional stabilization. Agglomeration processes occur only with a significant increase in concentration and heating time.